Fluctuating-charge models, dissociation

The Dissociation Catastrophe in Fluctuating-Charge Models and its Implications for the Concept of Atomic Electronegativity... 

The Dissociation Catastrophe in QEq-Type Fluctuating-Charge Models... 

The dissociation catastrophe can be interpreted as the consequence of an unrealistic assumption inherent in fluctuating-charge models, namely that pairs of atoms can exchange charge with equal facility regardless of their distance. This is true only in metallic phases, and therefore the extent to which this model fails to predict sensible charge distributions can be attributed to a fault in the underlying physics... 

In order to explain the temperature behavior of s far below the percolation onset a simple statistical model of polarization of nanometer-sized droplets containing negatively charged ions at the interface and positive counterions distributed in the droplet interior was developed (5,117). In the framework of this model, when the values of the droplet size and the constant of dissociation of ionic surfactant are both small, an experimentally monitored temperature increase in s can be explained by the temperature growth of the mean-square fluctuation dipole moment of a droplet. 

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